I think I finally have it figured out-- I'm a little slow.
OJ must have planned and executed the Vegas "sting" caper to prove he was just too damn dumb to have pulled off a murder or two. It also would have gained him back the merch he didn't want to let the Goldmans know that he had, since taking the "thives" to court would have required he invientory and value the items, on the record.
But I think it's an extension of the PR campaign sparked off with "If I Did It--" a chance to show off his dimwit side in an effort to re-establish his reputation as a victim of circumstance!